ES - CHAP. 2 THE ENVIRONMENT AND ORGANISMS ECOLOGICAL CONCEPTS

definitions || enumerations

ECOLOGY

Relationships between organisms & their environment. It is the study of the ways organisms interact with each other & with their non-living surroundings.

ECOSYSTEM

Refers to an interacting group of natural elements.

It also involves the relationship between:

• Biotic

• Abiotic

HOMEOSTASIS

Steady-state condition

BIOTIC COMPONENTS

Encompass all living organisms present in the ecosystem.

AUTOTROPHS

• “Self-feeders” or the “"producers.”

• They use energy from the sun/chemical energy to make their food.

PHOTOAUTOTROPHS AND CHEMOAUTOTROPHS

TYPE OF AUTOTROPHS

PHOTOAUTOTROPHS

Use the energy from sunlight to make their food in the process called photosynthesis.

Samples: Plants, Algae, Certain Bacteria

CHEMOAUTOTROPHS

Use chemical energy called chemosynthesis.

Samples: Some bacteria, Archaea

CHEMOTROPHS

Autotrophs that get their energy from inorganic substances, such as:

• Salt

• Iron

• Sulfur

Samples: Bacteria, Deep sea worms

HETEROTROPHS

• “Consumers”

These organisms can’t make food.

Primarily: Animals

SCAVENGERS AND DETRITIVORES

TWO TYPES OF DECOMPOSERS

DECOMPOSERS

Also unable to make their own food.

SCAVENGERS

Feed on soft tissues of dead animals.

Samples: Vultures, Raccoons

DETRITIVORES

Feed on detritus (remains of plants).

Samples: Earthworms.

ABIOTIC COMPONENTS

Nonliving features of the environment that influence an organism or group of organisms.

ENERGY

Required by all organisms to sustain life.

LIGHT ENERGY

Ultimate source of energy for almost all organisms in ecosystems.

VISIBLE LIGHT

Type of light that has greatest importance to all plants.

OXYGEN, CARBON DIOXIDE, NITROGEN

TYPES OF ATMOSPHERIC GASES

OXYGEN

used during animals’ respiration.

CARBON DIOXIDE

Used in plant photosynthesis.

NITROGEN

Made by available certain bacteria through various fixation processes.

PHYSICAL CHARACTERISTICS

Includes: Wind or air currents, Soil, pH, Temperature

PHYSIOGRAPHIC FACTORS

Associated with the physical nature of land surface/area.